Galactic Archeology

The Subaru Prime Focus Spectrograph (PFS) will undertake investigations into the formation and evolution of structure, from cosmological scales to the Local Group of galaxies. I will describe the astrophysical motivations for the planned observations of faint stars in the Milky Way, in its satellite galaxies and in M31, and the insight we hope to gain into how galaxies form and evolve, and into the nature of dark matter.